Segmentation Fault When Finding Black Point

[sohaibimran-10xe]

Hi I am trying to run this project on ubuntu 20.04 I have successfully built the project following the instructions but when processing the RAW images I get a segmentation fault. It occurs exactly at the point code tries to find the Black Level from the metadata.

Here is my shell code output

[nix-shell:~/Code/hdr-plus/build]$ ./hdrplus  dir_path out_img.png burst0_0.CR2 burst0_1.CR2

Opening dir_path/burst0_0.CR2
Opening dir_path/burst0_1.CR2
Black point: Segmentation fault (core dumped)

Any idea how to solve this?

[Titaniumtown]

I'll try and look at this issue this week, thank you for the report!

[Titaniumtown]

I can reproduce this issue locally. I'll start investigating.

Edit:

lldb:

Process 128835 launched: '/home/primary/projects/hdr-plus/build/hdrplus' (x86_64)
Opening ./../burst1_2.CR2
Opening ./../burst1_7.CR2
Black point: Process 128835 stopped
* thread #1, name = 'hdrplus', stop reason = signal SIGSEGV: address not mapped to object (fault address: 0x300000020)
    frame #0: 0x000000000040a3c7 hdrplus`RawImage::GetBlackLevel() const + 7
hdrplus`RawImage::GetBlackLevel:
->  0x40a3c7 <+7>:  movq   0x20(%rdi), %rsi
    0x40a3cb <+11>: movl   $0x2daa8, %edx ; imm = 0x2DAA8
    0x40a3d0 <+16>: movq   %fs:0x28, %rax
    0x40a3d9 <+25>: movq   %rax, 0x2dab8(%rsp)

code in question:

std::array<float, 4> RawImage::GetBlackLevel() const {
  // See https://www.libraw.org/node/2471
  const auto raw_color = RawProcessor->imgdata.color;
  const auto base_black_level = static_cast<float>(raw_color.black);

  std::array<float, 4> black_level = {
      base_black_level + static_cast<float>(raw_color.cblack[0]),
      base_black_level + static_cast<float>(raw_color.cblack[1]),
      base_black_level + static_cast<float>(raw_color.cblack[2]),
      base_black_level + static_cast<float>(raw_color.cblack[3])};

  if (raw_color.cblack[4] == 2 && raw_color.cblack[5] == 2) {
    for (int x = 0; x < raw_color.cblack[4]; ++x) {
      for (int y = 0; y < raw_color.cblack[5]; ++y) {
        const auto index = y * 2 + x;
        black_level[index] = raw_color.cblack[6 + index];
      }
    }
  }

  return black_level;
}

Edit 2: The issue has to do with RawProcessor. I'm investigating the api.

[BlueMatthew]

I find HDRPlus holding the reference of temporary object created in constructor function causes this fault. Changing type to "const Burst&" can fix this issue

https://github.com/BlueMatthew/hdr-plus/commit/03dfddd892d0aaf066e54a52bbf7e2765f75e71b

I can reproduce this issue locally. I'll start investigating.

Edit:

lldb:

Process 128835 launched: '/home/primary/projects/hdr-plus/build/hdrplus' (x86_64)
Opening ./../burst1_2.CR2
Opening ./../burst1_7.CR2
Black point: Process 128835 stopped
* thread #1, name = 'hdrplus', stop reason = signal SIGSEGV: address not mapped to object (fault address: 0x300000020)
    frame #0: 0x000000000040a3c7 hdrplus`RawImage::GetBlackLevel() const + 7
hdrplus`RawImage::GetBlackLevel:
->  0x40a3c7 <+7>:  movq   0x20(%rdi), %rsi
    0x40a3cb <+11>: movl   $0x2daa8, %edx ; imm = 0x2DAA8
    0x40a3d0 <+16>: movq   %fs:0x28, %rax
    0x40a3d9 <+25>: movq   %rax, 0x2dab8(%rsp)

code in question:

std::array<float, 4> RawImage::GetBlackLevel() const {
  // See https://www.libraw.org/node/2471
  const auto raw_color = RawProcessor->imgdata.color;
  const auto base_black_level = static_cast<float>(raw_color.black);

  std::array<float, 4> black_level = {
      base_black_level + static_cast<float>(raw_color.cblack[0]),
      base_black_level + static_cast<float>(raw_color.cblack[1]),
      base_black_level + static_cast<float>(raw_color.cblack[2]),
      base_black_level + static_cast<float>(raw_color.cblack[3])};

  if (raw_color.cblack[4] == 2 && raw_color.cblack[5] == 2) {
    for (int x = 0; x < raw_color.cblack[4]; ++x) {
      for (int y = 0; y < raw_color.cblack[5]; ++y) {
        const auto index = y * 2 + x;
        black_level[index] = raw_color.cblack[6 + index];
      }
    }
  }

  return black_level;
}

Edit 2: The issue has to do with RawProcessor. I'm investigating the api.

[Titaniumtown]

Great find @BlueMatthew! Fixed in: https://github.com/timothybrooks/hdr-plus/commit/3429723c204000ebfd9fc59792b62236448c167d